Field of the Invention
This invention pertains to medical instruments, and more particularly, to a pressure-sensing device suitable for use during hiatal hernia repair.
Hiatal hernia repair is needed in a large number of patients suffering from esophagitis. A hiatal hernia is defined as an enlarged opening at the point where the esophagus goes through the diaphragm. A relatively small hernia will permit the lowest part of the esophagus to slide upward into the chest while a larger hernia will let part of the stomach slide upward. In both cases the sphincter muscle has stretched and lost its capability of holding the stomach's acidic contents from refluxing or flowing back up into the esophagus.
A present repair technique for hiatal hernia is described in Hospital Practice, April 1972, Volume 7, No. 4 at pages 116-124 and in Time Magazine, Mar. 28, 1969 as well as in additional other articles in medical journals. The present preferred procedure is to stitch a part of the stomach to form an internal flap that prevents reflux. Ligaments and other tissues are attached where the esophagus joins the stomach (gastroesophageal junction) so that the junction is anchored permanently below the diaphragm. In addition, the sphincter muscle is tightened around the junction to prevent refluxing of the acidic contents of the stomach.
One of the difficulties in performing hiatal hernia repair is in determining whether the sphincter muscle has been tightened sufficiently to avoid reflux. To determine this in the past, postoperative pressure tests have been employed using various types of pressure-sensing tubes. Examples of such tubes are (1) a tube having a side-opening pressure-sensing hole which is encased in a flexible liquid filled balloon, (2) a tube containing axially spaced electrical strain gauges for simultaneously measuring esophageal, spincter, and gastric pressures, (3) a series of three tubes each with an independent pressure-sensing side hole, each side hole being spaced a different axial distance from the distal end of the collective tubes. None of these pressue-sensing device has proven satisfactory for intraoperative pressure sensing study. Thus, in the absence of a successful intraoperative pressure-sensing device, an inadequate sphincter repair was not detected until after the patient was removed from the surgery room sometimes requiring a second repair operation.